Saturday 1 October 2011 19.04 EDT
First published on Saturday 1 October 2011 19.04 EDT

Are you a parent who keeps an eye on who posts what on your child's Facebook account? Perhaps you know their password and sneak a look at their messages from time to time? You may even enjoy the trusted privilege of being a "friend".

Whatever the situation, social networking sites are a source of anxiety for parents, and now the latest trend will only add to their alarm. Children are staying way ahead of attempts by parents and schools to police their online activity And the latest ruse is a secret, fake-name Facebook account.

"Some kids will have two or even three," says Dr Barbie Clarke, of the youth research agency Family Kids and Youth, who monitors online trends among schoolchildren in the UK.

"Their habits change and we're seeing them progress from the obvious lie about their age – allowing them to use Facebook in the first place – to this second or third identity. It's usually driven by Mum picking up on something from their page and raising it with them. They want privacy and they want a secret world." She is very relaxed about Facebook use by children, saying she thinks they are generally more sensible and supportive of each other than they get credit for. "A second identity can be used for nastiness, to anonymously bully, but generally it's about secrecy – like a secret diary, or dialogue they can have away from parents and other family members."

Many children use school facilities to access their fake accounts. "I have two," admits Harriet, 14.

After she upset a fellow student with a posting she says was "meant as a joke", her mother banned her from using the site. "I tell everyone my new name and get loads of friends as soon as," said Harriet. "My mum is on Facebook and she'd see if my name was up. I don't do it on our computer at home, only at ICT in school and on my iPhone. It's not as good on the iPhone for seeing pictures, but you can use it late at night in bed. You can't not be on it, or you just don't have friends."

Concerns over children setting up Facebook accounts and lying about their age are not new. There is no legislation in the UK to stop under-13s using such sites. Facebook's terms and conditions, which were put in place to comply with US law, are unenforceable in practice. This year, its founder Mark Zuckerberg said he would challenge those restrictions.

Many schools fail to monitor pupils' use of technology, he said. "It's the biggest issue we have, schools not taking parents' concerns seriously."

But Clarke cautioned against alarmism. "I think there is a lot more fear among parents than there need be. Actually, children are quite supportive of each other most of the time. It's the lonely, isolated child we need to worry about. Of course there are issues with bullying – there always have been and there always will be. Technology makes it much more immediate and personal."

She cited the example of one boy who turned to more worrying online activities after his parents prevented him using Facebook. "He was feeling very socially excluded. He'd come into school and all the social arrangements had been made without him on Facebook the night before. Ironically, that boy was using Xbox Live and playing games with complete strangers on the internet, which was probably far more dangerous."

Others take a different view. Lyn Cook, 49, from Surrey, banned her 15-year-old daughter from using the site. "She does mind," says Cook. "She understands my point of view but every so often she will ask again. Then I show her stories in newspapers about cyberbullying and 'trolls'. At her school there was a site set up to rubbish one of the teachers, so she sees all that going on, the bullying, the little remarks that might not be meant nastily but really upset someone. I just think she is too young, too immature to handle all that stuff."

But the study by Family Kids and Youth suggests children all too easily find ways around such bans.

"The kids are wiser and know they'll be caught bullying or trolling, so they're all using faked-name accounts," said one teacher at a Sussex secondary school. "I'd applaud any parent who tried to ban their children from Facebook but, as my kids say, 'good luck with that!'"